-Albumin is in the plasma
-Partly responsible for blood viscosity and osmotic pressure; acts as a buffer; transports fatty acids, free bilirubin, and thyroid hormones
-Important in regulation of water movement between tissues and blood.

What do globulins do?

- Present in blood plasma
- Transports lipids, carbohydrates, hormones and ions like iron and copper; antibodies and complement are involved in immunity.

1. The globin chains of hemoglobin are broken down to individual AAs and are metabolized or used to make new proteins.
2. Iron is released from the heme. The heme is converted to biliverdin which converts to bilirubin.
3. Fe is transported in combination w/ transferrin in the blood to various tissues for storage or transported to the red bone marrow and used in prod. of new hemoglobin
4. Free bilirubin is transported in the blood to the liver
5. Conjugated bilirubin is excreted as part of the bile into the sm. intestine.
6. Bilirubin derivatives contribute to the color of feces or are reabsorbed from the intestine into the blood and excreted from the kideys in the urine.

- First studied in rhesus monkeys
- Types:
-- Rh positive: Have these antigens present on surface of RBCs
-- Rh negative: Do not have these antigens present
- Hemolytic disease of the newborn (HDN)
--Mother produces anti-Rh antibodies that cross placenta and cause agglutination and hemolysis of fetal RBCs

-Plasminogen is converted by thrombin, factor XII, tissue plasminogen activator (t-PA), urokinase, or lysosomal enzymes to the active enzyme plasmin.
-Plasmin breaks the fibrin molecules and therefore the clot into smaller pieces, which are washed away in the blood or are phagocytized.

What are the different clotting factors?

- 12 factors for intrinsic, extrinsic, and common paths, numbered I to XIII (factor VI is extinct)
- all but 3 are synthesized in the liver
- II, VII, IX, X require vitamin K

- Consists of plate of fibrous connective tissue between atria and ventricles
- Fibrous rings around valves to support
- Serves as electrical insulation between atria and ventricles
- Provides site for muscle attachment

- Resting potential is only about –55mV
- Sodium “leak” channels slowly depolarize
- Threshold is only about –40 mV

How does the AV node contract?

- A-V node delays the electrical signal
Allow time for ventricles to fill
Bundle of His (A-V bundle) conducts impulse to ventricles
Left and Right bundle branches provide rapid transmission to ventricles

- First heart sound or “lubb”
-- Atrioventricular valves and surrounding fluid vibrations as valves close at beginning of ventricular systole
- Second heart sound or “dupp”
-- Results from closure of aortic and pulmonary semilunar valves at beginning of ventricular diastole, lasts longer
- Third heart sound (occasional)
-- Caused by turbulent blood flow into ventricles and detected near end of first one-third of diastole

1. Sensory neurons carry action potentials from baroreceptors to the cardioregulatory center. Chemoreceptors in the medulla oblongata influence the cardioregulatory center.
2. The cardioregulatory center contols the frequency of action potentials in the parasym. neuons extending to the heart. The parasym. neurons ↓ HR.
3. The cardioregulatory center controls the frequency of action potential in the sympathetic neurons extending to the heart. Symp. neurons ↑ HR and stroke vol.
4. The cardioregulatory center influences the frequency of action potentials in the symp. neurons extending to the adrenal medulla. The symp. neurons ↑ the secretion of Epi and some NorEpi into the general circulation. These ↑ the HR and stroke vol.

1. ↑ in blood pH, often caused by ↓ in blood CO2, causes parasympathetic stimulation of heart and a ↓ in sympathetic stimulation of heart and adrenal medulla (↓ Epi and NorEpi), leading to ↓ HR and stroke volume.
2. A ↓ in blood pH, caused by ↑ blood CO2, ↓ parasympathetic stimulation of the heart and ↑ sympathetic stimulation of heart and adrenal medulla, leading to release of Epi and NorEpi and ↑ of HR and stroke vol.

– Tubes of endothelium on the basement membrane.
– 40-50 μm in diameter, 0.2-0.3 mm in diameter in small
veins.
– Venules collect blood from capillaries and transport it
to small veins.

What are the properties of medium and large veins?

– Medium veins collect blood from small veins and deliver it to large veins.
– Large veins transport blood from medium veins to
the heart.
– Tunica intima and media is thin, tunica adventitia is
predominant.

What is the vasa vasorum?

In arteries and veins greater than 1 mm in diameter, nutrients are supplied by small blood vessels called “vasa vasorum”.

– Thrombosis; the formation or presence of a blood clot within a blood vessel.
– Embolism; the sudden obstruction of a blood vessel
by an embolus.
– Hemorrhage; a large discharge of blood from the
blood vessels.

• Tendency for blood vessel volume to increase as blood pressure increases.
• More easily the vessel wall stretches, the greater
its compliance.
• Compliances = increase in volume (ml) / increase in pressure (mmHg)
• Venous system has a large compliance and acts as a blood reservoir

• Driving force for filtration is hydrostatic pressure.
• Blood pressure in a capillary is the capillary
hydrostatic pressure (CHP).
• BP grad. falls from 35 to 10 mm HG at the venous end of capillary.
• Filtration occurs primarily at the arterial end of a capillary where CHP is highest.

What is reabsorbtion in capillary exchange?

• Occurs as a result of Osmosis.
• The greater the osmotic pressure of a fluid is, the greater is the tendency of water to move into that fluid.
• Blood colloid osmotic pressure (BCOP)

• BP is almost 0 mm HG in the right atrium.
• It averages about 100 mm HG in the aorta.
• Pressure in vessels above and below the heart is affected by gravity.
• In a standing position, hydrostatic pressure caused by gravity increases blood pressure below the heart and decreases pressure above the heart.

• Nervous ctrl of arterial BP is important in min-to-min
regulation of local BF.
• BP must be good enough to
cause BF in capillary at rest, exercise or shock.
• By nervous regulation, blood can be shunted from one area to another.
• e.g., in blood loss, BF to
visceral and skin is reduced,
to allow BF through the
capillaries of brain and
cardiac muscle.
• Sympathetic vasoconstrictor
fibers less prominent in SKM,
cardiac muscle and the brain
and more in the kidney, gut,
spleen and skin.

• Movement of fluid from interstitial spaces into
capillaries in response to decrease in blood pressure to maintain blood volume.
• Important in dehydration/ or when a large volume of saline is administered.

What is the stress-relaxation response?

- Adjustment of smooth muscle of blood vessel walls to respond to change in blood volume.
- decrease in blood volume, decrease in blood pressure, decrease in force applied to VSMC, then SMCs contract and reducing the volume of blood vessels resists a further decline in BP.

1. Platelet adhesion occurs when von Willebrand factor connnects collagen and platelets.
2. The platelet release reaction is the release of ADP, thromboxanes, and other chemicals that activate other platelets.
3. Platelet aggregation occurs when fibrinogen receptors on activated platelets bind to fibrinogen, connecting the platelets to one another. A platelet plug is formed by the accumulating mass of platelets.

1. Action potentials originate in the SA node and travel across the wall of the atrium from the SA node to the AV node.
2. Action potentials pass through the AV node and along the AV bundle, which extends from the AV node, through the fibrous skeleton, into the interventricular septum.
3. The AV bundle divides into right and left bundle branches and action potentials descend to the apex of each ventricle along the bundle branches.
4. Action potentials are carried by the Purkinje fibers from the bundle branches to the ventricular walls.

What are the permeability changes during an action potential in cardiac muscle?